1. All parts before installed must be cleaned well, especially the position ring, O ring notch, screw, gasket surface, bearing and bearing lubrication area
2. When the impeller of sand pump is serious rusty (especially the back side of impeller) or serious abrasion we must replace the impeller
3. After inspecting the radial jump to confirm if the pump shaft is curved. If the radial jump height is over 0.05mm we have to change the pump shaft. There should be no nick and notch on bearing or oil seal. All screws on pump shaft should be in good condition, otherwise we need to replace the pump shaft
4. If there is obvious nick or serious abrasion on anti-abrasive shaft sleeve we need to change the anti-abrasive shaft sleeve
5. If there is serious abrasion on bearing we need to replace new bearing. New bearing size and model must be completely same with original one and don't open the package before operation
6. Mechanical seal moving ring and static ring if seriously abrasived we need to change the seal assembly
7. All O rings and seals have to be changed if uninstalled. The gasket can be used as before if no damage
